Screening of antibodies to varicella-zoster virus in leukemic patients: comparison of commercial methods of enzyme-immunoassay and fluoroimmunoassay

Commercial methods of enzyme immunoassay and fluoroimmunoassay for the detection of varicella-zoster antibodies were compared using serum samples from individuals in a program of bone marrow transplantation. The correlation was 93.4%. Enzyme immunoassay showed to be more sensitive. Both methods are applicable to the detection of varicella-zoster antibodies. However, when fluoroimmunoassay is used, we recommend the confirmation of negative results by a sensitive enzyme immunoassay.

Evaluation of a latex agglutination test for screening antibodies to rubella virus

The performance of a commercial latex agglutination test for screening rubella antibodies was investigated, using two panels of selected serum samples especially designed for a careful evaluation of sensitivity. Three false negative results were obtained on samples with very low levels of antibody. However, the test had higher sensitivity than the hemagglutination inhibition test and fluoroimmunoassay when samples were tested undiluted. False positive results were not obtained, and prozone reactions were not observed. The test is a very practical method for screening rubella antibodies in primary health care units.

Comparison of four methods for screening of cytomegalovirus antibodies in normal donors and immunocompromised patients

Three commercial methods (enzyme immunoassay, fluoroimmunoassay and latex agglutination) and a complement fixation test were compared for detection of cytomegalovirus antibodies using a panel of 490 serum samples from blood and organ donors, from immunocompromised patients and paired sera from five patients with recent cytomegalovirus infection. An indirect immunofluorescence test for antibodies to cytomegalovirus was used for classifying samples giving discrepant results by any of the four methods. All methods showed high sensitivity and specificity, but the enzyme immunoassay and the latex agglutination tests had the highest sensitivity. Latex agglutination is recommended for large-scale screening of cytomegalovirus antibodies in blood and organ donors. Negative results obtained by latex agglutination should be confirmed by sensitive enzyme immunoassays.

Poliomyelitis in Spain, 1982-1984: virologic and epidemiologic studies

The authors present a detailed study of poliomyelitis in Spain for the years 1982, 1983, and 1984. The 50 cases reported have been epidemiologically classified following World Health Organization guidelines. Virus was isolated from 43 of these cases. Intratypic characterization was done using specifically absorbed antisera classifying the strains as non-Sabin-like and Sabin-like. The neutralizing antibodies in whole and fractionated sera were also determined. The largest number of paralytic poliomyelitis cases, 28, was found in children in the first year of life. Thirty of the cases were unvaccinated children. Poliomyelitis was not detected in adults during the period described. Wild strains isolated were type I and III, primarily from Gypsies. There was a significant incidence of vaccine-associated cases in recipients, as well as in contacts during 1982 and 1983. The cases were located in the Mediterranean and Southern zone. In 1984, total and vaccine-associated cases dropped dramatically.

Aseptic meningitis due to varicella-zoster virus: serum antibody levels and local synthesis of specific IgG, IgM, and IgA

We used an indirect enzyme immunoassay to describe the evolution of serum levels and the intrathecal production of IgG, IgA, and IgM antibodies to varicella-zoster virus (VZV) in eight patients with a syndrome of acute aseptic meningitis (AAM) and evidence of intrathecal production of VZV-specific IgG antibodies. Four of the eight patients showed no cutaneous zoster while hospitalized. Our results suggested an etiologic relation between VZV and AAM in all cases. Furthermore, we observed some differences in the pattern of evolution of antibodies in serum and cerebrospinal fluid in relation to the presence or absence of cutaneous lesions in our patients. These differences could reflect different pathogenic mechanisms in the spread of VZV to the central nervous system and in the production of the AAM syndrome.

Fluoroimmunoassay for detection of rubella-specific immunoglobulin M: comparison with indirect enzyme immunoassay and mu-chain capture

The performance of a commercially-available method of fluoroimmunoassay (Rubella M FIAX, International Diagnostic Technology, Santa Clara, Calif.), designed for the detection of rubella-specific immunoglobulin M, was tested with 137 selected sera, including 52 from cases of primary rubella, 29 from healthy pregnant women, 21 containing rheumatoid factor, and 35 from cases of infectious mononucleosis (IM) caused by Epstein-Barr virus. The results were compared with those obtained by commercial indirect enzyme immunoassay (EIA) and EIA anti-mu chain capture tests. The fluoroimmunoassay technique showed a satisfactory level of sensitivity, but low values had to be interpreted with caution as false-positive results were detected with sera with rheumatoid factor and from IM cases, even after preliminary treatment of sera with the anti-human immunoglobulin G antisera provided in the kit. On the other hand, no false-positive results in the analysis of IM sera were seen in the EIA anti-mu chain capture method. Because of its sensitivity and specificity, we recommend the use of the latter technique for the diagnosis of primary rubella.